• Title/Summary/Keyword: two-phase-lags

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Rayleigh waves in orthotropic magneto-thermoelastic media under three GN-theories

  • Parveen Lata;Himanshi
    • Advances in materials Research
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    • v.12 no.3
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    • pp.211-226
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    • 2023
  • The present work is considered to study the two-dimensional problem in an orthotropic magneto-thermoelastic media and examined the effect of thermal phase-lags and GN-theories on Rayleigh waves in the light of fractional order theory with combined effect of rotation and hall current. The boundary conditions are used to derive the secular equations of Rayleigh waves. The wave properties such as phase velocity, attenuation coefficient are computed numerically. The numerical simulated results are presented graphically to show the effect of phase-lags and GN-theories on the Rayleigh wave phase velocity, attenuation coefficient, stress components and temperature change. Some particular cases are also discussed in the present investigation.

Effect of two-temperature in an orthotropic thermoelastic media with fractional order heat transfer

  • Lata, Parveen;Himanshi, Himanshi
    • Composite Materials and Engineering
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    • v.3 no.3
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    • pp.241-262
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    • 2021
  • In this article, we studied the effect of two-temperature in a two-dimensional orthotropic thermoelastic media with fractional order heat transfer in generalized thermoelasticity with three-phase-lags due to thermomechanical sources. The boundary of the surface is subjected to linearly distributed and concentrated loads (mechanical and thermal source). The solution of the problem is obtained with the help of Laplace and Fourier transform techniques. The expressions for displacement components, stress components and conductive temperature are derived in transformed domain. Numerical inversion technique is used to obtain the results in physical domain. The effect of two-temperature on all the physical quantities has been depicted with the help graphs. Some special cases are also discussed in the present investigation.

Effect of rotation on Stoneley waves in orthotropic magneto-thermoelastic media

  • Parveen, Lata;Himanshi, Himanshi
    • Wind and Structures
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    • v.35 no.6
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    • pp.395-403
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    • 2022
  • The present research is concerned with the study of Stoneley wave propagation at the interface of two dissimilar homogeneous orthotropic magneto-thermoelastic solids with fractional order theory of type GN-III with three phase-lags and combined effect of hall current and rotation. With the help of appropriate boundary conditions the secular equations of Stoneley waves are obtained in the form of determinant. The characteristics of wave such as phase velocity, attenuation coefficient and specific loss are computed numerically. The effect of rotation on the Stoneley wave's phase velocity, attenuation coefficient, specific loss, displacement components, stress components and temperature change has been depicted graphically. Some particular cases are also derived in this problem.

Non-simple magnetothermoelastic solid cylinder with variable thermal conductivity due to harmonically varying heat

  • Zenkour, Ashraf M.;Abouelregal, Ahmed E.
    • Earthquakes and Structures
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    • v.10 no.3
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    • pp.681-697
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    • 2016
  • The model of two-temperature magneto-thermoelasticity for a non-simple variable-thermal-conductivity infinitely-long solid cylinder is established. The present cylinder is made of an isotropic homogeneous thermoelastic material and its bounding plane is traction-free and subjected to a time-dependent temperature. An exact solution is firstly obtained in Laplace transform space to obtain the displacement, incremental temperature, and thermal stresses. The inversion of Laplace transforms has been carried out numerically since the response is of more interest in the transient state. A detailed analysis of the effects of phase-lags, an angular frequency of thermal vibration and the variability of thermal conductivity parameter on the field quantities is presented.

Plane harmonic waves in fractional orthotropic magneto-thermoelastic solid with rotation and two-temperature

  • Himanshi;Parveen Lata
    • Coupled systems mechanics
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    • v.12 no.2
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    • pp.103-125
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    • 2023
  • The present research is focused on the study of plane harmonic waves in a two-dimensional orthotropic magneto-thermoelastic media with fractional order theory of generalized thermoelasticity in the light of two-temperature and rotation due to time harmonic sources. Here, we studied three types of waves namely quasi-longitudinal (QL), quasi-transverse (QTS) and quasi thermal (QT) waves. The variations in the wave properties such as phase velocity, attenuation coefficient and specific loss have been noticed with respect to frequency for the reflected waves. Further the value of amplitude ratios, energy ratios and penetration depth are computed numerically with respect to angle of incidence. The numerical simulated results are presented graphically to show the effect of fractional parameter based on its conductivity (0<α<1 for weak, α=1 for normal, 1<α≤2 for strong conductivity) on all the components.

Two-temperature thermoelastic surface waves in micropolar thermoelastic media via dual-phase-lag model

  • Abouelregal, A.E.;Zenkour, A.M.
    • Advances in aircraft and spacecraft science
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    • v.4 no.6
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    • pp.711-727
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    • 2017
  • This article is concerned with a two-dimensional problem of micropolar generalized thermoelasticity for a half-space whose surface is traction-free and the conductive temperature at the surface of the half-space is known. Theory of two-temperature generalized thermoelasticity with phase lags using the normal mode analysis is used to solve the present problem. The formulas of conductive and mechanical temperatures, displacement, micro-rotation, stresses and couple stresses are obtained. The considered quantities are illustrated graphically and their behaviors are discussed with suitable comparisons. The present results are compared with those obtained according to one temperature theory. It is concluded that both conductive heat wave and thermodynamical heat wave should be separated. The two-temperature theory describes the behavior of particles of elastic body more real than one-temperature theory.

Two-Dimensional Mechanism of Hovering Flight by Flapping Wings (날개짓에 의한 공중정지비행의 이차원 메카니즘)

  • Kim, Do-Kyun;Choi, Hae-Cheon
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.759-764
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    • 2003
  • Numerical simulations are conducted to investigate the mechanism of hovering flight by single flapping wing, and to examine the effect of the phase difference between the fore- and hindwings in hovering flight by two flapping wings. The numerical method used is based on an immersed boundary method in Cartesian coordinates. The Reynolds number considered is Re=150 based on the maximum translational velocity and chord length of the wing. For single flapping wing, the stroke plane angles are $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, $75^{\circ}$ and $90^{\circ}$ and the downstroke angles of attack are varied for each stroke angle. Results show that for each stroke plane angle, there is an optimal angle of attack to maximize the vertical force. Below the stroke angle of $60^{\circ}$, wake capturing reduces the negative vertical force during the upstroke. For two flapping wings, The phase lags of the hindwing are $0^{\circ}$, $90^{\circ}$, $180^{\circ}$ and $270^{\circ}$. The amplitudes of the stroke are 2.5 and 4.0 times the chord length at each phase lag. The results show that maximum vertical force is generated when the phase lag is zero, and the amplitude of the vertical force is minimum at the phase lag of $180^{\circ}$.

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Transversely isotropic thin circular plate with multi-dual-phase lag heat transfer

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.343-351
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    • 2020
  • The present research deals with the multi-dual-phase-lags thermoelasticity theory for thermoelastic behavior of transversely isotropic thermoelastic thin circular plate The Laplace and Hankel transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution are computed in the transformed domain with the radial distance and further determined in the physical domain using numerical inversion techniques. The effect of rotation and two temperature are depicted graphically on the resulting quantities.

Orthotropic magneto-thermoelastic solid with higher order dual-phase-lag model in frequency domain

  • Lata, Parveen;Himanshi, Himanshi
    • Structural Engineering and Mechanics
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    • v.77 no.3
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    • pp.315-327
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    • 2021
  • Here, in this research we have studied a two dimensional problem in a homogeneous orthotropic magneto-thermoelastic medium with higher order dual-phase-lag heat transfer with combined effects of rotation and hall current in generalized thermoelasticity due to time harmonic sources. As an application the bounding surface is subjected to uniformly distributed and concentrated loads (mechanical and thermal source). Fourier transform technique is used to solve the problem. The expressions for displacement components, stress components and temperature change are derived in frequency domain. Numerical inversion technique has been used to obtain the results in physical domain. The effect of frequency has been depicted with the help of graphs.

Thermoelastic deformation properties of non-localized and axially moving viscoelastic Zener nanobeams

  • Ahmed E. Abouelregal;Badahi Ould Mohamed;Hamid M. Sedighi
    • Advances in nano research
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    • v.16 no.2
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    • pp.141-154
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    • 2024
  • This study aims to develop explicit models to investigate thermo-mechanical interactions in moving nanobeams. These models aim to capture the small-scale effects that arise in continuous mechanical systems. Assumptions are made based on the Euler-Bernoulli beam concept and the fractional Zener beam-matter model. The viscoelastic material law can be formulated using the fractional Caputo derivative. The non-local Eringen model and the two-phase delayed heat transfer theory are also taken into account. By comparing the numerical results to those obtained using conventional heat transfer models, it becomes evident that non-localization, fractional derivatives and dual-phase delays influence the magnitude of thermally induced physical fields. The results validate the significant role of the damping coefficient in the system's stability, which is further dependent on the values of relaxation stiffness and fractional order.